Two-piece tooth for excavating apparatus



Feb. 23, 1960 c. SENNHOLTZ 2,925,673

TWO-PIECE TOOTH FOR EXCAVATING APPARATUS Filed Feb. 12, 1957 2' Sheets-Sheet l EIEIEIEIEJEIEIQEIEIQQI I zz I'm/M2227;-

M/ff/ M @Ziarae /s Feb. 23, 1960 TWO-PIECE TOOTH FOR EXCAVATING APPARATUS Filed Feb. 12, 1957 2 Sheets-Sheet 2 Jae/6162291 Cfmres Semafif;

@l Mdf Jjw fiii aeqs United States Patent TWO-PIECE room FOR EXCAVATING APPARATUS Charles E. Sennholtz, Chicago, 111.

Application February 12, 1957, Serial No. 639,718

1 Claim. (Cl. 37-142) This invention relates to digging teeth for an excavating bucket or dipper and more particularly to a two-pieced tooth having a removable blade.

In excavating apparatus of this type the parts most subject to wear are the teeth on the digging edge of the bucket or dipper unit, and therefore it becomes decidedly advantageous to be able to replace these parts when they are too badly worn for effective use. However, since the teeth are subjected to considerable stress they must be rigidly mounted and firmly held in place.

It has been proposed to form the teeth as a solid part of the digging unit and provide each tooth body with a removable tip or blade that may absorb the wear. This arrangement achieves a firm, rigid digging tooth whose worn portion can be replaced, but leaves the problem of how to attach the removable blade to the fixed tooth body. The common practice is to weld these parts together, but this expedient makes replaceability difficult and the welding heat tends to alter the hardness characteristics of the parts when the blade is installed.

Therefore, it is an object of the invention to provide an improved two-piece tooth which has a digging blade that is firmly and rigidly seated in place to resist the forces encountered in heavy duty digging. It is also an object to secure the digging blade of a two-pieced tooth of the above type for simple removal. It is a more detailed object to provide a two-pieced tooth of the above character wherein the blade is removably secured by a simple well-protected fastener that is completely effective although of sufiiciently light construction as to enable attachment and detachment by a light-duty wrench.

It is a further object to provide an improved two-piece tooth of the above character having a unitary digging blade structure that encases and protects the fixed portion of a tooth.

-It is an additional object of the invention in one of its aspects to provide a digging blade of the above type that will deflect and roll the material being dug, and thus reduce the wearing load imposed on the lip of the excavating apparatus.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings, in which- Figure l is an elevation view of an excavating unit provided with a two-piece tooth constructed according to the present invention;

Figure 2 is a somewhat reduced sectional plan view taken along line 2-2 of Figure 1;

Figure 3 is an enlarged elevation view of a single tooth without a blade and is taken along line 3-3 of Fig. 2;

Figure 4 is a perspective view of the blade portion of one of the two-piece teeth shown in Figs. 1 and 2;

Figure 5 is a transverse sectional view taken along line 55 of Fig. 7;

Figure 6 is an exploded perspective view of the twopiece tooth and blade assembly of the present invention;

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Figure 7 is a longitudinal sectional view taken along the line 7--7 in Fig. 2.

While the invention will be described in connection with the preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment but, on the contrary, intend to cover such alternative embodiments and constructions as may be included in the spirit and scope of the intended claim.

Turning now to Figs. 1 and 2, there is shown a bucket or dipper 10 forming part of an excavating unit. The bucket supporting and operating means are not shown and may be conventional. Formed along the digging edge 11 of the bucket 10 are a plurality of digging teeth 20. For mounting the teeth 20 at the digging edge 11, the bucket includes a floor plate 21 which overlies the bottom of the bucket 10 and is rigidly secured thereto, as by a row of bolts 22. Integrally formed at the relatively thick forward edge of floor 21 is a series of spaced tooth mounting supports 23. In the present embodiment four such supports are provided.

Each tooth support 23 comprises a body 24, which is U-shaped in cross-section, extending forwardly of the floor 21 and terminating in an annular socket portion 25. For the purpose of accurately positioning and rigidly supporting the teeth 20, each cylindrical socket 25 ends in a blunt V-shaped tip 26, shown in Fig. 3, and has two generally rectangular recesses 27 and 28 formed in its top and bottom respectively. The latter, as will be seen, mates with corresponding portions on the tooth body.

Turning our attention next to the teeth 20 (see especially Figs. 4 and 6), it will be observed that each tooth includes a body portion 30 comprising a shank 31 and a forward wedge-shaped portion 32. The cylindrical shank 31 is adapted to fit snugly within the annular portion 25 of a corresponding support 23. So that the tooth body 30 may be accurately and rigidly mounted in a support 23, generally rectangular bosses 33, 33a are formed integrally with the body portion 30 and are proportioned to fit snugly within the recesses 27 and 28 formed in support 23. To further insure accurate and rigid tooth alinement, the wedge-shaped portion 32 has a shallow V-shaped notch 34 formed at its rearward surface to accurately abut the tip 26 of a socket 25. The tooth body 30 is fixed to bucket 10 by being properly positioned within its support 23 and welded into place.

In accordance with the present invention each twopieced digging tooth comprises, in addition to the tooth body 30, a replaceable tip or blade 40 formed as a hollowed wedge to closely surround the forward portion 32 of body 30, and means are provided to draw the hollowed wedge into tight wedging contact with the body 30 and lock it into position. In the present embodiment, the replaceable blade 40 has a forward, hollowed wedge portion 45, having inside dimensions enabling it to snugly surround the wedge-shaped portion 32 of a tooth body 30, and upper and lower extensions 41 and 42 respectively, which form continuations of the upper and lower wedging surfaces of the blade portion 45. The nose or digging edge of blade 40 has a depending lip portion 43, in the preferred embodiment illustrated, which results in a configuration known as a drop snout tooth.

It will be seen that the replaceable tip 40 shields and surrounds the tooth body 30 so that all of the wear incurred by the digging edge during normal excavating operations will be borne by the tip. It should also be noted that the wedging fit of blade 40 on the tooth body 30 prevents play between the two parts, and that the forces incurred during digging operaions tend to wedge the blade 40 even more tightly into position.

Further in accordance with the invention, the blade 40 is locked into proper position on the tooth body 30 by a single, light duty fastening, which permits the blade 40 to be easily removed and replaced. In the present embodiment, this fastening comprises a long bolt 50 whose head 51 is adapted to fit within and engage the sides of a T-slot 52 formed within the hollowed wedge portion 45 of blade 40. When in place, the bolt 50 extends through a longitudinal hole 53 formed in the tooth body 30. A suitable nut 54 is provided to draw the bolt head 51, and thus the blade 40, tightly into contact with the tooth body 30.

Forming the T-slot 52 is a cavity portion 55 constructed as an integral part of the blade 40. To allow the blade 40, having the portion 55 within it, to slide snugly into engagement with the body portion 30 a recess 56 is formed in the forward wedge-shaped portion 32 of the body 30. The recess 56 is sufficiently large to allow the portion 55 of blade 40 to slide easily within it.

With regard to assembly procedure, the bolt 50 is slid partially within the opening 53 formed in the body portion 30. The bolthead 51 is hooked within the T-slot 52 and the blade 40 is then slid to snugly overlie the wedgeshaped forward portion 32 of tooth body 30. Finally, the nut 54 is tightened to securely lock the parts of the tooth into one rigid unit. It should be noted that when the tooth body 30 is secured to a support 23, only the very end of bolt 50 and the nut 54 are exposed. However, these elements of the fastening means are well protected within the upstanding arms of the tooth support body 24 which, it will be remembered, is U-shaped in cross section. Thus, the fastening means which holds the removable blade in its place is completely protected from wear or accidental damage and yet is easily accessible by a socket wrench for the convenient removal and replacement of blade 40.

It is a feature of the invention in one of its aspects to provide means on the replaceable digging blade 40 to deflect upwardly slabs of material being dug so as to curl the material up and away from the digging edge of the bucket 10. In the present embodiment, these means comprises a pair of spaced parallel ridges 60 and 61 formed integrally with the top surface of blade 40 at approximate right angles to the direction of digging. It has been found that the deflecting and curling action caused by the ridges 60, 61 appreciably decreases the wear on a digging edge of the bucket or dipper with which the tooth 20 is used. While the illustrative embodiment includes only two ridges and 61, it is apparent that any convenient number of such ridges may be provided.

I claim as my invention:

In an excavating unit having a digging edge, the combination comprising, a socket portion having an opening therethrough formed integrally with said unit along said edge, a tooth body fitted into said socket portion opening and having a wedge-shaped forward portion extending outwardly from said edge, said tooth body and said socket portion having interfitting abutting parts for fixing the position of the body on the unit and the body being shaped to form a smoothly continuing extension of the socket portion, said body having a longitudinally extending bolt hole therethrough, a replaceable blade formed as a unitary, hollowed wedge snugly fitted over the forward portion of said tooth body so as to dispose wall portions of said blade outwardly of the top, bottom and opposite sides of theinterfitting body and socket portion, a cavity-definingwall within said hollowed wedge having a T-slot therein 'alined with said bolt hole, a bolt extending from said slot through said hole and releasably securing the blade onto the unit, integral extensions of said blade wall portions, outwardly of the top and bottom of the body and socket portion extending back from said blade, and integral ridges on said wall and the extension above said tooth, said ridges being generally parallel to said edge and spaced rearwardly from the forward portion of said body.

References Cited in the file of this patent UNITED STATES PATENTS 888,046 Sherrerd May 19, 1908 1,218,841 Dietz Mar. 13, 1917 1,419,047 Hanks et al. June 6, 1922 1,545,621 Turner July 14, 1925 1,783,350 Watts Dec. 2, 1930 2,167,425 Page July 25, 1939 2,393,706 Page Jan. 29, 1946 

